My wife is on tamoxifen but is allergic to lactose. are there any lactose free tamoxifen on the market?

No: The small amount of lactose used in compounding the tamoxifen should not bother her. There are no lactose-free medications at all in the United States. It is not a problem due to the small amount in a tablet. Dyes in tablets are another issue. Make sure it is the lactose and not dye in the pill that is a concern. Talk to your prescriber they should know about this.

Not an allergy: Lactose is a sugar, and as such you cannot be allergic to it. People who don't make the enzyme needed to digest sugars are intolerant, meaning consuming quantities will produce symptoms like bloating, gas, cramps, loose stools. Lactose intolerant people can consume it in small quantities & be symptom free. You do not need to avoid it like you would things that break you out/ bee stings/etc.